The disclosed embodiments of the present invention relate to processing packets, and more particularly, to a packet processing apparatus and method capable of generating modified packets by modifying payloads of specific packets identified from received packets.
In contrast to the analog television system using analog signals to carry audio and video information, a digital television (DTV) system sends and receives audio and video information by means of digital signals. For example, at the transmitter end, the audio and video information to be transmitted is first packetized into transport stream (TS) packets, and then the TS packets are modulated and transmitted by broadcasting techniques. Regarding the receiver end, a demodulator block is required for demodulating a modulated input signal received via a tuner and an antenna to reproduce TS packets from the modulated input signal, and a demultiplexer block following the demodulator block is required to identify and demultiplex packets to store video packets, audio packets, program and system information protocol (PSIP) packets into respective storage spaces. Next, the video packets, audio packets, PSIP packets will be processed to acquire the desired video information, audio information, and the program and system information, respectively.
In a conventional design, all of the received packets will be demultiplexed and then stored. However, certain packets demultiplexed and stored may carry unwanted information for a following signal processing state, which inevitably increases the packet processing burden of the following data processing stage.